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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19547 results found.

  1. GRB 000301C: K' Observations
  2. GRB000301C - Host galaxy not detected in R (?)
  3. Optical observations of GRB000301c
  4. GRB000301C, Radio observations
  5. GRB000301C, Radio observations
  6. GRB 000301c near-IR observations
  7. GRB 000301C, UBVRI field photometry
  8. GRB000301C, near-infrared observations (JHK' photometry)
  9. GRB 000301C: OT confirmed
  10. GRB000301c optical observations
  11. GRB000301C
  12. GRB 000301C : Optical Candidate
  13. HST Observations of GRB 990712
  14. GRB 000214 near-IR observations
  15. GRB 000214, Radio Observations
  16. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  17. GRB000210, Radio Observations
  18. GRB 000115, BVRI field photometry
  19. GRB000214: BeppoSAX GRBM and WFC Detection
  20. Optical observations of GRB000210
  21. GRB000210 X-ray afterglow
  22. GRB000214: X-ray afterglow candidate
  23. GRB000214 refined BeppoSAX-WFC position
  24. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  25. Correction to Chandra Position of GRB000210 afterglow
  26. Optical observations of the Chandra X-ray source for GRB000210
  27. GRB000210, Radio Observations
  28. GRB000210: possible afterglow detection with BeppoSAX NFI
  29. GRB000201, Radio Observations
  30. GRB000210: BeppoSAX GRBM and WFC Detection
  31. GRB000201 Optical Observations
  32. GRB 000126, optical observations
  33. IPN localization of GRB000126
  34. IPN annulus for GRB000115
  35. GRB991216, UBVRIJHK field photometry
  36. GCN resumes full operations
  37. GRB 991216: Detection of the Host and/or Absorber Galaxy
  38. GRB 991216 RXTE ASM Observations
  39. GRB 991217 (SAX J2303.2+0015) Optical observations
  40. Chandra observation of the X-ray afterglow of GRB991216
  41. SAX J2303.2+0015 Optical observations
  42. IR observations of GRB991216
  43. GRB 991217 (SAX J2303.2+0015) Optical observations
  44. GRB 991216 Radio Observations
  45. GRB 991208 Infrared Detection
  46. GRB991216
  47. GRB 991216--Summary of RXTE Observations
  48. GRB 991216 Optical Observations
  49. GRB 991216, optical observations
  50. GRB 991208 SAO-RAS Spectroscopy
  51. SAX J2303.2+0015: an x-ray/GRB?
  52. GRB 991216, Optical Transient
  53. GRB991216 ('Beethoven Burst') B, R, and K Observations
  54. GRB991216, infrared observations
  55. GRB 991208 optical observations
  56. GRB 991216 Optical Observation
  57. GRB 991216: Extremely bright BATSE burst
  58. R-band Observations of GRB991208 at TNG
  59. GRB991208, optical observations
  60. GRB 991208, Optical Observation
  61. GRB991208, optical observations
  62. IPN localization of GRB991208
  63. Optical Observations of GRB991105
  64. GRB991106: BeppoSAX/BATSE results
  65. BeppoSAX NFI Observation of GRB991106
  66. GRB 991106, radio observations
  67. GRB991106: the first BeppoSAX short GRB detection?
  68. GRB 991106 Optical Observations
  69. GRB991106, optical observation at SAO-RAS
  70. GRB 991106, LOTIS Optical Observations
  71. GRB991105: SAX-GRBM/-WFC detection
  72. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  73. GRB 991014, Optical Observations
  74. GRB 991014 - BeppoSAX NFI observations
  75. GRB 991014, radio observations
  76. GRB 991014, Optical Observations
  77. GRB 991014, optical observations
  78. Optical Observations of GRB990907
  79. GRB990907: BeppoSAX follow up and X-ray afterglow
  80. GRB990907 and 990908
  81. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  82. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  83. GRB990806 BeppoSAX follow up
  84. GRB 990806 Optical observations
  85. GRB 990806, optical observations
  86. GRB 990806, Optical Observations
  87. GRB990806: possible X-ray afterglow, BeppoSAX
  88. GRB 990712 Optical Observations
  89. GRB 990712
  90. Late-time HST/STIS Observations of GRB 990510
  91. BeppoSAX NFI Observation of GRB990705
  92. BeppoSAX NFI Observation of GRB990705
  93. GRB 990705, R-band observations
  94. GRB990704: SAX-NFI results summary
  95. GRB990704 radio and optical observations
  96. GRB990704
  97. GRB990704, optical observations
  98. GRB990704: possible X-ray afterglow
  99. GRB990704
  100. GRB990704: BeppoSAX detection

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